Water droplets of "tread throw", hereinafter referred to as "throw" are thrown from rotating tires of vehicles traveling at high speed on wet surfaces and impact against surfaces of the vehicle, causing the throw droplets to fragment into smaller droplets of spray. This spray impairs the visibility of drivers of these and other vehicles during wet conditions. Tests have demonstrated erratic directional control by drivers of following cars and trucks which are enveloped in this spray, especially from the large commercial trucks and tractor-trailer combinations which are moving ahead of them or beside them as they travel on wet roadways. Drivers of these large vehicles also have difficulty seeing, via their rear view mirrors, through the spray generated by their own vehicles, which occasionally causes accidents as they change lanes.
Good devices have evolved for over-the-wheel and behind the wheel installation to reduce the spray formation. Several patents have also been issued to condense the spray, formed over the wheel from high velocity throw, as it is blown laterally toward the adjacent lane. These latter devices are called side skirts. This patent application describes an improved side skirt. Prior attempts include the following. Schlegel (UK) Limited in UK Patent No. 2,074,109 of 1980, uses bristles to condense the laterally moving spray effectively, however, in a cross wind, the falling water blows against the tire to spray again. Sparks in U.S. Pat. No. 4,585,242 of 1984 creates a down draft with his side skirt to drive the spray downward toward the road surface. McKenzie in U.S. Pat, No. 4,398,739 of 1983 uses rubber buttons to condense spray, but again lets it fall off the skirt to blow against the tire in a cross wind. Lightle in U.S. Pat. No. 4,382,606 of 1983 uses vertical ridges facing the wheel to cause the condensate to fall directly downward, again blowing onto the tire in a cross wind. Clutter in his U.S. Pat. No. 4,436,319 of 1984 collects the spray in an enclosed fender and diverts the water to fall toward the center of the vehicle. Jurges in his U.S. Pat. No. 4,427,208 of 1984 provides a fender with symmetric wedges facing the throw above the tire, the wedges lying parallel to the rotational planes of the tire, having decreasing height for those that are outside the edge of the tire, to the extent that much of the water must run downwardly and blow against the tire in a cross wind. Goodall in U.S. Pat. No. 4,290,619 of 1981 provides "screens" consisting of several channels beside the wheel into which the spray can flow, thereafter condensing and being wind-driven rearward to a vertical discharge pipe and thence to be carried laterally toward the center of the vehicle with water from the rear screen behind the wheel to be ejected inside the tracks of the tires in a rearward direction. The largely enclosed horizontal screens therein will fill with dirt from the roadway and cease to function. Finally, Crowley, in UK Patent No. GB 2,146,598 A of 1985 uses horizontal ridges on a rigid rear panel behind the wheels, the panel facing the flow from the tire directly and the ridges carrying the water laterally to vertical discharge pipes. Although one of his designs is flexible, it is so designed to allow enclosed lateral channels to open and accept the throw, the largely enclosed channel carrying the condensate laterally to the drain(s), the large panel being held rigidly either by the drains or by anti-lift devices.